预热温度对燃烧合成Fe掺杂β-SiC粉体的微观组织和吸波性能的影响

The effect of preheating temperature on microstructure and absorption property of Fe doped β-SiC powders by combustion synthesis

采用整体预热燃烧合成法,以硅粉和炭黑为原料,铁粉为掺杂剂,聚四氟乙烯为助燃剂,在0.1MPa的氮气气氛中分别在不同预热温度下合成Fe掺杂β-SiC粉体。通过X射线衍射、扫描电子显微镜和电子能谱对合成粉体进行了微观表征。同时在8.2~12.4GHz频率范围内进行了介电性能测试,并对其吸波性能进行了计算。结果表明,随着预热温度的升高,合成的β-SiC粉体的晶格参数随之减小,其介电性能随之降低；当预热温度为1300℃,匹配厚度为2mm时,合成粉体的吸波性能在X波段达到最佳。

Fe-dopedβ-SiC powders have been synthesized by overall preheating combustion synthesis under dif-ferent preheating temperature,using silicon powders and carbon black as the raw materials,iron powder as dopant and PTFE as the chemical activator,respectively.The microstructure of prepared powders has been characterized by XRD,SEM and EDS.The electric permittivity of prepared powder has been determined and the microwave absorption property has been calculated in the frequency range from 8.2GHz to 12.4GHz.Re-sults show that the lattice constants and dielectric property of the preparedβ-SiC decrease with increasing pre-heating temperature.The SiC powder synthesized under preheating temperature of 1300℃ with 2mm matching thickness presents the best microwave absorption property in the X-band.